The advance in manufacturing technology relating to halogen incandescent lamps makes it possible to equip hand-held flashlights and the like, supplied from primary or rechargeable batteries. By use of halogen incandescent lamps as the light source, about four times as much light can be obtained than that derived from standard miniature incandescent lamps. Consequently, a substantially brighter light can be obtained. Halogen incandescent lamps, however, when placed into standard flashlights, have a beam path which may not be suitable for optimum utilization. Usually, such flashlights have a simple reflection system including a parabolic reflector; no lenses or diaphragms are usually provided. Upon changing the position of the reflector with respect to the lamp, light cones of different aperture angle can be obtained. Unfortunately, the intensity of illumination across the light cone is highly variable and, frequently, just in the center of the illuminated area, a "black hole" appears, with a minimum of illumination being available from the central region.
Use of halogen incandescent lamps, entirely apart from the higher brightness obtainable for an illuminated region, opens a new field of utility for flashlights. Flashlights with halogen incandescent lamps can be used for signalling over substantial distances, due to their brightness; further, upon properly placing the halogen incandescent lamp in an optical system, precise spot illumination can be obtained, and the spot illumination used, for example, to trace outlines, to be used as a lightmarker in connection with optical presentations or to decode symbols. Such use, however, requires that the light beam or light cone which is generated have a very low cone angle with a sharp transition or boundary zone. Ordinary flashlights or flash lamps do not permit such use.